Well casing setting and backing-off coupling



Feb. 8, 1938. J. c. SINGLETON WELL CASING SETTING AND BACKING-OFF COUPLING \N\\\\\\ It 7 3 9 l 6 1 l i r m .d e m 3 aufi N H y 1 LE i i T I l L n 8: I D I 0" Z John C. Singleton Patented Feb. 8, 1938 WELL CASING SETTING AND BACKING-OFF COUPLING John Christian Singleton, Vinton, Lat, asslgnor of one-fourth to Ivy Cunniif, Lake Charles, La.

Application April 16, 1937, Serial No. 137,360

7 Claims.

My invention 'relatesto the setting of casings in oil wells. It has heretofore been the general practice in setting a casing in a. well to make upthe last joint loose in the coupling so that when the casing has been allowed to set the desired time, the connection may be backed off easily. In such practice it often happens that the threads in the coupling become galled or crossed and difliculty is experienced in breaking the connection, often resulting in backing the casing off several joints below the desiredplace. To avoid this a tool that is known as a back-off tool is employed; this tool must be made up on a smaller size joint of pipe and run inside the casing below the place at which the casing is to be broken apart so as to hold the bottom joints from turning. This is troublesome and requires additional labor and time. If the threads are burred in coupling where the joint is broken out, it makes it hard to start new threads in it again.

My invention therefore has for its prime object to provide means to overcome the objections above noted.

Generally, the'invention comprises a specifically designed right and left hand threaded casing setting tool having a thread protection guide skirt, and a special combination-coupling with two right hand casing threads and a special left hand thread to fit the setting tool and grooved to receive a rubber gasket ring to cooperate with the skirt in protecting .the inside or. top casing threads of the combination-coupling from dirt and injury.

Other objects will in part be obvious and in part be pointed out hereinafter.

To the attainment of the aforesaid objects'and ends the invention still further resides in the novel details of construction, combination and arrangement of parts, all of which will be first fully described in the following detailed description, and then be particularly pointed out in the appended claims, reference being had to the accompanying drawing, in which:-

' Figure 1 is a vertical longitudinal section of a casing with my invention in use.

Figure 2 is a half vertical section and half elevation of the casing setting tool.

Figure 3 is a view similar'to Figure 2 of the combination-coupling.

In the drawing, in which like numbers of reference indicate like parts in all figures, l and II represent the top and adjacent sections of the well casing which are of the usual construction and have opposing ends right hand threaded.

To the lower one, ll, of the sections l and ll is coupled, by means of a suitable collar 20, the combination-coupling ll which constitutes an essential part of my. invention. This coupling ii is of three principal inside diameters, the greatest being provided with an internal left 5 hand thread I3, the part of intermediate diam- .eter having the internal (female) right hand casing thread l5, and the part of the least diameter having the external right hand casing thread i9. 4

The threaded parts It and I5 are separated by (preferably) a ground beveled area l4 acting as a seat to .be engaged by a corresponding seat 8 on the casing setting tool. At the upper end the coupling ll may have a smooth entrant wall l2. 15 Just below the threads I5 is a groove It to receive a rubber packing-ring I1 and below the groove I6 is a. beveled seat Hi to be engaged by the corresponding end seat ID of the. setting tool.

The setting tool comprises a body having a go bore of two diameters, the largerbore being provided with a right hand casing thread 5 (female).

- Below the larger end 3 of the tool there is provided a left hand (male) thread I to screw into the thread ll, there being a beveled seat 8 below this thread and a skirt 9 with the beveled end it below the seat 8. The bore 8 of lesser diameter is like unto that of the casing sections I and ii,

' and the bore of least diameter 22 of the combination-coupling H. The entrant end of the tool 3 may be smooth as atA to facilitate assembling.

In using my invention, the combination-coupling is securely joined by the collar '20 to the last joint (2|) or section of the casing and remains there. The tool I is screwed onto the lower end of the casing section I and tool 3 is then screwed left hand on left hand part of the combination-coupling, i. e., threads I are screwed onto threads ii. The casing is then run in the well.

After the casing has set the desired time, a strain is put on the casing and measurement taken to determine the length of space nipple to use between combination-coupling, II and the casing head. The setting tool (Figure 2) is then backed out of coupling II by turning casing section i in a right hand direction. This leaves a clean new thread (I!) into which to screw the space nipple (not shown). The larger bell-like part l2-l3 serves as a guide so that the space nipple will easily enter the special coupling ll.

From the foregoing description, taken in connection with the accompanying drawing. it is th ught that the construction, operation and ad- 60 right hand threaded connection with the adjavantages of the invention will bereadily understood by those skilled in the art.

What I claim is:

1. In a well casing setting, the combination with the top casing section of a combinationcoupling secured thereto by a threaded connection of one direction, say right hand, said combination-coupling having a female casing thread of the same direction as that of the threaded connection, and having above the female easing thread an enlargement with a female thread of a direction opposite to that of the aforesaid threaded connection, a setting tool comprising an upper portion, an intermediate portion and a skirt constituting a lower portion,said upper portion having a female casing thread of the same direction as that of said threaded connection and said intermediate portion having a male thread of a direction corresponding to that of the enlargement of said combination-coupling, said skirt projecting into and protecting the female casing threads of said combination-coupling when said tool and coupling are assembled,

2. In a well casing setting, the combination with the top casing section of a combinationcoupling secured thereto by a threaded connection of one direction, say right hand, said combination-coupling having afemale casing thread of the same direction as that of the-threaded connection, and having above the female casing thread an enlargement with a female thread of a direction oppositeto that of the aforesaid threaded connection, a setting tool comprising an upper portion, an intermediate portion and a skirt constituting a lower portion, said upper portion having a female casing thread of the same direction as that of said threaded connection and said intermediate portion having a male thread of' a ,direction corresponding to that of the enlargement of said combination-coupling,

- said skirt projecting into and protecting the female casing threads of said combination-coupling when said tool and coupling are assembled, said combination-coupling having a groove with a ring-gasket at the lower end of its female casing thread to cooperate with said skirt to seal oil the casing threads against dirt.

3. In the art of setting well casing, a combination-coupling and a setting tool having left hand threaded connection with one another and cent ends of the well casing section, said coupling including a female casing thread and said tool including means to cover and protect said female casing thread when said tool 'and coupling are assembled.

4. In the art of setting well casing, a combination-coupling and a setting tool having left hand threaded connection with one another and right hand threaded connection with the adjacent ends of the well casing section, said coupling including a female casing thread and said tool including means to cover and protect said female casing thread when said tool and coupling are assembled, said means comprisinga skirt on the tool extending above and below the female casing thread of the coupling and means at the ends of the skirt for sealing oh the female casing threads of the coupling.

5. In the art of setting well casing, a mombination-coupling and a setting tool having left hand threaded connection withone another and right hand threaded connection. with the adjacent ends of the well casing section, said coupling including a female casing thread and said tool including means to cover and protect said female casing thread when said tool and coupling are assembled, said means comprising a skirt on the tool extending above and below the female casing thread of the coupling and means at the ends of the skirt for sealing off the female casing threads of the coupling, said sealing off means comprising beveled seat surfaces.

6. In the art of setting well casing, a combination-coupling and a setting tool having left hand threaded connection with one another and right hand threaded connection with the adia cent ends of the well casing section, said coupling including a female casing thread and said tool including means to cover and protect said female casing thread when said tool and coupling are assembled, said means comprising a skirt on the tool extending above and below the female casing thread of the coupling and means at the ends of the skirt for sealing oil the female casing threads of the coupling, said sealing means v including a flexible gasket carried by the coupling to embrace the skirt,

7. In the art of setting well casing, a combination-coupling and a setting tool having left hand threaded connection with one another and right hand threaded connection with the adjacent ends of the well casing section, said coupling including a female casing thread and said tool including means to cover and protect said female casing thread when said tool and coupling are assembled, said means comprising a skirt on the tool extending above and below the female casing thread of the coupling and means at the ends of the skirt for sealing oil the female casing threads of the coupling, said sealing oif means comprising beveled seat surfaces and a rubber ring-gasket embracing the lower end of the skirt and carried by said coupling.

JOHN CHRISTIAN SIN GLETON 

